Balancing machine



Oct. 15,` 1929.- c. R. soDERBERG 1,731,357

BALANCING MACHINE v v Filed neo. 21. 1922 ATTORNEY Patented oct. 15,1929 UNITED STATES; PATENT' OFFICE ARL RICHARD SODERBERG, F EDGEWOO-DPARK, PENNSYLVANIA, ASSIGNOB TO WESTINGHOUSE ELECTRIC & MANUFACTURINGCOMPANY, A CORPORATION OF i PENNSYLVANIA BALANGING MACHINE' Applicationfiled December 21, 1922. Serial No. 608,371.

My invention relates to balancing machines,l more especially to machinesfor testing the unbalanced mass in rotors, such as armatures fordynamo-electric machines.

It is among the objects of this invention to provide a device of theabove-designated character that shall be adapted to indicate the amountand relative location of unbalanced. masses in a body being tested. v

It is a further object of thisinvention to provide a device which shallbe mechanically' simple and accurate for determining such unbalance andwhich shallbe adapted, inv particular, to the testing of rotors in largequantities in an eIicient and expeditious manner.

In my copending application, Serial No. 593,732, filed Oct. 11, 1922, Ihave disclosed a device for testing rotors which isespecially adapted toindicate unbalance in small high speed bodies, as the degree of error inthe manipulation of the device is so small as to make possible thedetection of relatively small unbalanced mass in the body tested'.

The centrifugal forces exerted on the body. producevibration whichindicates the degree of imbalancev in the body tested, and a movablefulcrum upon which the body is supported permits of determining thedegree of unbalance about a given transverse axis. Thisv arrangementreduces the number of weights to be applied so that the total amount ofcorrection becomes aminimum. v u My present invention is directed to adevice for testing rotating bodies for unbalance'mass which embodies themovable fulcnum of the above-mentioneddevice and whichufurther employsAan. adjustable counterweight by which the amount and the relativelocation Vof unbalance. are determined. By means of the counterweight,itis possible to introduce .an artificial unbalance which counteractsthe centrifugal forces produced by theunbalanced masses of the rotatingbody. When these forces are equivalent and opposed, the g wheel 18. Thelifting ]acks 15 function to vibration of the movable support upon whichthe rotor is mounted ceases.

4 angularly movable members, and the resultant 60' of the magnitude ofthe displaced counteractof its movable support The counter- 'balancingweights of the device comprises two ing forces produced by 'the weightsindicates the longitudinal plane in which the correction weight is to beapplied to the rotor. The magnitude of unbalance isla function of theangle between the counterweights and is indicated by suitablegraduations on the counterweight supports.

In the accompanying drawing constituting a part hereof and in which likereference characters ldesignate like parts,

Figure 1 is a side elevational view of a balancing machine embodying theprinciples of my invention;

taken along theline II--II of Fig. 1;

Fig. 3 is an end elevational view of a counterbalancing device; A A

Fig. 4' is a longitudinal sectional view thereof; and

Fig. 5 is a diagrammatic view of the relative positions of thecounterbalancing weights, the resultant of which indicates the amplitudeof the unbalance mass of the body tested.

Referring to Fig. 1, the device comprises a stationary support 1, havinga vertically m'ovable bed 2, -secured thereto by a plurality oftransverse spring bars or plates 3. A movable .fulcrum 4 is interposedbetween the bed 2 and the support 1 and comprises a transverse beam 5,provided with projections 6 at the base near its respective ends whichare adapted to slide in correspondingly shaped ways 7 of the supports 1.A plurality of grooved rollers 8'are rotatably mounted in the upperportion of the beam 5 vand are adapted tw engage the knife edges 9,formed integrally with the movable bed 2. The

bea-m 5 is provided with a threaded opening 10, which is adapted toengage a screw 12,

geared to a hand wheel 13 by which the fulcrum is actuatedlongitudinally of the bed and support. 15 are connected by a worm gear1G to'a lon- `itudinal rod 17, which is connected to a'hand raise thebedv2 outof contact with the fulcrum 4. indicating device, such as a dialndieator'20, is secured to the support 1 Fig. 2 is a cross-sectionalviewthereof,A

A plurality of lifting jacks and is adapted to engage a projecting arm10 21, securedto the movable bed 2 to indicate the degree of vibration.

The bed 2 is provided with a plurality of roller-bearing supports 23having rollers 25 rotatably mounted thereon Which are adapted torotatably supportI a body to be tested, such as a rotor 26. The rotor2.6 is secured, by a chuck or clamp 27 Which is iiexibly connected,

through a iiexible coupling 28, to a motor 29 Which may be regulated toany desired speed. One end of the motor shaft 30 is connected, by a pairof spur gears 31, of a one-to-one ratio, to a shaft 32 journaled on thebody 2 by journal brackets 33 and 34. The shaft 32 is provided with acounterbalancing device comprising a plurality of parallel disks 36 and37, which are formed integral with eXtension sleeves 38 and39,1'espectively (Fig. 4). The sleeve 38V is provided with .acounterbore 40, by Which it rests against a spacing `collar or shoulder41 of the shaft 32, and

t-he other end of the sleeve 38 is retained on the shaft by a similarcollar 42. rllie disks 36 and 37 are provided with counteriveights 43and 44, respectively. The disks are adapted to be moved angularlyzhy aplurality of adjusting sleeves 45 and 46, respectively,

which are loosely keyed lon the sleeve 3 8 and the shaft 32.

The sleeves 45 and. 46 are provided with threaded outer portions 49 and50 to effect a threaded engagement With tlie sleeves 39 and 38,respectively, and they are further provided With grooves 51 adapted toreceive trunnions of shifting levers 52, which are connected, byscreW-and-nut mechanism (not shown) to the hand Wheels 53 and 54 (Fig.1). A collar 55, having an indicator 56 attached thereto, is mounted onthe shaft 32 against the outer face of the disk 36. The indicator 56 isprovided With a movable sleeve 57, which is connected, by links 58 and59, to the disk 36 and a projecting pin 6() secured to the disk 37,which extends through a slot 61 provided in the disk 36. The links 58and59 are pivoted to their respective disks in radial alinement With thecounter-Weights thereof and' maintain a central relation of theindicator 56 With respect to the weights 43 and 44, irrespective oftheir relative positions. The

outer surface 63 of the disk 36 is provided with graduations, and anindicator 64 is secured to the disk 37.

Referring to F ig. 5, the Weights 43 and 44, as indicated, are sodetermined that the centrifugal forcesl created are equal. Theirresultant is, therefore, always in the bisecting line 65 between theradiito the centers accessible parts for the'addition of correctionWeights, the fulcrum 4 is moved in either,

one ofthese planes, say plane,A-A. The

motor 29 is energized to actuate the rotor 26,

The counterbalancing rlhe readingof the indicator 64 then indi-t 3@cates the magnitude of unbalance of the Weights 43 and 44, which isproportional to the amount of correction to be made in the rotor, andthe indicator 56 indicates the longitudinal plane in which thecorrection is to be applied on the surface B-B. rlhe bed 2 is thenraised from the fulcru-m 4 by means of the lifting jacks 15, and thefulcrum 4 is moved in the plane B-B, Where the operation is duplicatedand the correction applied to the plane A-A.

The corrections need not be applied, -ut the amount and location simplyindicated'on the rotor to speed up the o eration, and the correctionsmay be made after the rotor has been removed from the machine.

It will be readily understood, from they above description of myinvention'that a device formed in accordance therewith provides anefficient means for testing rotors, such as armatures and otherhigh-speed bodiesfor unbalance, and an important advantage of thisdevice lis that no application of Weights is necessary in order toobtain the condition of balance. This device is especially adapted inefor the testing of rotors in large quantities,

as it permits of making such tests in rela, tively short periods oftime.

Although I have described a specific embodiment of my invention, it Willbe obvious to those skilledyin the art that various modifications may bemade in the details of con'- struction. For instance, the stationarysupport, the movable bed, the yielding spring mounting, and the liftingjacks may be of any suitable construction to meet the requirements ofsizes and types of rotors to be tested, and the counterbalance mechanismmay be of any suitable design to effect a counterbalancingi of forcesproduced by the unbalance mass in the rotating body. The

manipulating devices employed in this ma-V chine may be of any suitabletype to produce the proper functioning of adjustments.- These andotherchanges may be made Without departing from the principles hereinset forth.

I claim as my inventionz- 1. A balancing machine comprising a sta'- itionarysupport, a bed yieldingly supported thereon, a movable fuleruminterposed be- 4 supporting a body to tionary support, a

' tating body.

. tionary support,

tween said'bcd and said support, means on said bed foi' rotatablymounting a body to be tested, means for rotating said body, means forcounteracting the moment of the centrifugal force exerted upon said `bedby the imbalance of'the rotating body about a given transverse axis andmeans for adjusting 'the counter-acting means While the body isrotat-ing.

2. A balancing machine comprising a stationary support, a bed yieldinglysupported thereon, a movable fulcrum interposed between said bed andsaid support, means for moving said fulcruin longitudinally of said bed,means on said bed for rotatably mount'- ing a body to be tested, meansfor rotating said body, means for counteracting the centrifugal forceexerted upon said bed by the imbalance of the rotating body and meansfor adjusting the counter-acting means While the body is'rotating. i.

3. A balancing machine comprising a stationary support, a movable bedfor rotatably be tested, a .movable fulcrum between said bed and saidsupport,

indicating means .rotatably mounted on the bed for determining themagnitude of theI imbalance in the body being tested,'said indicatingmeans consisting of a plurality of movable weights relatively adjustablehaving graduated di `ks in co-operative alinement to indicate theamplitude of their relative positions,'means for adjusting the weightswhile the body is rotating, and means for determining the relativelocation ofV the unbalance.

4. A balancing machine comprising a stabed yieldingly mountedV thereonwhich is adapted to rotatably support a'bodyv to be tested, a movablefulcruin between said bed and said support, indicating meansA fordetermining the magnitude of the imbalance in the body being tested,said indicating means consisting of a plurality of movable weights thatarerelatively adjustable and rotatably mounted on the bed havinggraduated disks in co-operative alinement to indicate the'relativepositions of said weights, and said locating means consisting of a'nindicator automatically adjustable with .said movable Weights whichindicates the longitudinal. plane in which the unbalance exists.

5. A balancing machine comprising a staa bed secured by a plurality ofsprings to said support, a movable fulcrum between said bed and saidsupport, means-for lifting said bed out of contact with said fulcrum,means for rotatably mounting a body to be testel on said bed, and meansrotatably mounted on the bed for determining the amount and location ofunbalance in the romachine comprising a stao. A balancing bed secured bya plurality tionary support, a

- of'springs to said support, a movable fulcrum between said bed andsaid support, means for lifting said bed out of contact with'saidfulcrum, means for rotatably mounting a body to be tested on said bed,and means rotatably mounted on the bed for determining the amount 'andlocation of unbalance in the rotating body, about thereof.

7. A balancing machine comprising a stationary support, a bed secured bya plurality of transverse springs to said support, a fulcruin movablysecured between said-bed and said support, a screw-and-nut mechanism foractuating said fulcrum, a screw-andsnut mechanism geared to a pluralityof vertical j acks for lifting said bed out of contact with saidfulcrum, means on said bed for rotatably mounting a body to be tested,and indicating means for determining the amount and location ofunbalance vin'thc rotating body about a given transverse axis thereof.

8. A balancing machine comprising a stationary support, a bed secured bya plurality of transverse springsto said support, a fulcrum movablysecured between said bed and said support, av sciew-and-nut mechanismfor actuating said fulcrum, a screw-and-nut mechanism geared to aplurality of vertical jacks for lifting said bed-out of said fulcrum,means on said bed for rotatably mounting a body to be tested, andindicating means for determining the amount and locationof imbalance inthe rotating body about a given transverse axis thereof, and adjustingmeans for countei'acting the centrifugal forces produced on the movablebed by the unbalance of the rotating body.

9. In a balancing machine for testing rotors, the combination with anoscillatory bed, of a movable fulcrum member for supporting the bed, abalancing head mounted on the bed, said balancing head comprising tworotatably mounted balancing weights .each disposed to be moved angularlywith respectto a rotor being balanced and means for adjusting theweightswhile the rotor and the weights are rotating.

v10. In a balancing machine for testing rotors, the combination with anoscillatory bed, of va balancinghead mounted on the bed, said balancinghead comprising two rotatably mounted balancing Weights, each disposedto be moved angularly along paths of different radii with respect to a.rotor being balanced while the rotor is rotating, and means dicating theresultant unbalanced moment of the balancing Weights and the angularposition thereof. v

11. In a counterbalancing device for balancing machines, a plurality ofrotatably mounted balancing Weights disposed to be ad-v justed angularlyin the same transverse plane and alongl paths of different radii whilelthey are rotating. y

12. A balancing machine comprising a a given transverse axis forincontact with base, an oscillatable bed mounted on the base, means onthe bed for rotatably supporting a rotor to be balanced, alongitudinally movable fulcrummember interposed between the bed and thebase in a transverse plane of the rotor, a plurality of balancingweights rotatably mounted on the bed and disposed to rotate in a planeparallel to the fulcrum plane and means for adjusting the weightsangularly while the rotor is rotating to neutralize the moment of theunbalanced mass in the rotor with respect to the fulcrum axis.

13. A balancing machine comprising a base, an oscillatable bed mountedon the base, means on the bed for rotatably supporting a rotor to bebalanced, a fulcrum member interposed between the bed and the base, aplurality of balancing weights rotatably mounted on the bed and disposedto rotate in synchronism with the rotor to be tested and means foradjusting the weights angularly While the rotor is rotating toneutralize the turning moment about the fulcrum axis that is exerted bythe unbalanced mass in the rotor.

14. Ina machine for balancing rotors, the combination with a stationarysupport, a bed yieldingly mounted on the support and means on the bedfor rotatably mounting a rotor to be tested, of a fulcrum memberinterposed between the bed and the support and disposed to be movedlongitudinally relative to the bed to limit the movement of the bed toangular oscillation about an axis in a transverse plane of the rotorbeing tested, means for counteracting the moment about the fulcrum axisof the unbalanced centrifugal force exerted upon the bed by the body andmeans for adjusting the counteracting means while the body is rotating.f

In testimony whereof, I have hereunto subscribed my name this 13th dayof December, 1922.

CARL RICHARD SODERBERG.

